The present invention relates to an image forming apparatus, and more particularly, to an image forming apparatus in which the installation structure of a laser scanning unit, a photosensitive drum and a transfer unit is improved to prevent their vibration.
In a conventional image forming apparatus such as a color printer or color copier, in order to reduce internally created vibration and driving error, a flywheel is installed on one side of a rotator without an additional buffer so that the moment of inertia is raised. This is, however, a passive design. An expensive precision motor may also be employed. Such conventional modes have been used with limited improvement, and as a result, they have problems of jitter, color blurring or color smearing.
FIG. 1 shows such a conventional image forming apparatus.
Referring to FIG. 1, the apparatus includes a paper carrier 2 having a roller 3 and a guide plate 4 which together convey sheets of paper to a main body 1, a photosensitive drum 5, a laser scanning unit 6 for emitting a laser beam to photosensitive drum 5 to form an electrostatic latent image, a developing unit 7 for supplying toner to the electrostatic latent image formed on photosensitive drum 5, a transfer unit 8 for transferring the toner supplied to photosensitive drum 5 to the paper, and a fixing unit 9 for fixing the toner transferred onto the paper. Such an apparatus has no additional buffer.
In the conventional image forming apparatus, since the components are all located in the main body, during the driving of the components, the vibration created by the paper carrier or fixing unit is transmitted to the laser scanning unit, photosensitive drum and transfer unit which affects image quality.
Due to the vibration, the position or the laser beam of the laser scanning unit is altered, impeding the electrostatic latent image from being precisely formed on the photosensitive drum, and the image formed on the photosensitive drum with toner cannot be precisely transferred to a sheet of paper. This creates color blurring or color smearing, deteriorating image quality.
In addition, due to the vibration, toner is scattered in the apparatus when the toner is supplied from the developing unit to the photosensitive drum. This contaminates the apparatus.